Reshape and rearrange data frame in r

Question

Year = c(2013, 2013, 2014, 2014, 2015, 2014, 2013, 2015, 2015);districts = c("A", "B", "C", "B","A", "A", "C" ,"C","B"); sex = c("M"," F", "M", "F","M"," F","M", "F", "F"); age = c("age1",'age2', 'age3','age4', "age5","age6", "age7","age8","age8");df = data.frame(Year, districts, sex, age); df

我想采用以下格式：

Year = c(2013, 2013, 2013, 2014, 2014, 2014, 2015, 2015, 2015); districts = c("A", "B", "C", "A","B", "C", "A" ,"B","C"); sex = c("M"," F", "M", "F","F"," M","M", "F", "F"); age = c("age1",'age2', 'age3','age4', "age5","age6", "age7","age8","age8");df = data.frame(Year, districts, sex, age) ;df

Answer 1

We could arrange the columns and then check whether the next value in 'age' is the same as the current

library(dplyr)
res <- df %>% 
         arrange(Year, districts) %>% 
         mutate(age = paste0('age', cumsum(c(TRUE, age[-1] != age[-n()]))))


all.equal(res, out)
#[1] TRUE

NOTE: After removing the white spaces in 'sex' column in the original dataset ('df') and the expected output ('out'). Also, converted to character class for easy comparison